Synthesis and crystal structure of 1,2,4-trifluoro-3,5,6-tris(triisopropylsilyl)benzene

Fluorinated Dewar benzene (1,2,4-trifluoro-3,5,6-tris(triisopropylsilyl)bicyclo[2,2,0]-hexa-2,5-diene) efficiently prepared from fluoro(triisopropylsilyl)acetylene was thermochemically or photochemically transformed into the corresponding highly crowded fluorinated benzene (1,2,4-trifluoro-3,5,6-tris(triisopropylsilyl)benzene) in excellent yield. The molecular structure of the crowded benzene was determined by X-ray crystallography.